Drill bit with tangential jet



g- 1964 E. B. WILLIAMS, JR 3,144,087

DRILL BIT WITH TANGENTIAL JET Filed Jan. 5, 1961 2 Sheets-Sheet 1 a J; I/5 I L g 4 I /E ,9

1 52 4 149 T f f IN V EN TOR.

A 770 RNEK 1964 E. B. WILLIAMS, JR 3,144,087

DRILL BIT WITH TANGENTIAL JET Filed Jan. 5, 1961 2 Sheets-Sheet 2INVENTOR. 6 [dz/4M5 WWW/407.9%: 6 3 BY ATTOENEK United States Patent3,144,087 DRILL BIT WITH TANGENTIAL JET Edward B. Williams, Jr.,Greenville, Tex., assignor of onethird to Edward B. Williams III,one-third to Joseph W. Williams, and one-third to David B. Williams, allof Greenville, Tex.

Filed Jan. 5, 1961, Ser. No. 80,830 3 Claims. (Cl. 175-339) Thisinvention relates to drill bits for rotary drilling of bore holes intoearth formations, and particularly to drill bits of the type havingtoothed cutters for cutting through the various formations encounteredin drilling such bore holes, the present invention being an improvementof the drill bit illustrated and described in my copending applicationSerial No. 67,957, filed November 8, 1960, and matured into Patent No.3,113,630, dated December 10, 1963.

The cutters of this type of drill bit are usually arranged to roll inpaths concentrically with the rotary axis of the drill stern, so thatall of the cutters are used to cut the full gauge of the bore hole,consequently one cutter rolls over the same circular path as a precedingcutter. The result is that the teeth of one cutter must act on theformation through the cuttings produced by the other cutters. Usuallythe bodies of the drill bits are equipped with ports to discharge one ormore jets of drilling fluid in contact with the bottom of the hole,which are supposed to clean the cuttings from under the cutters andcarry the cuttings upwardly within the bore hole, however, such jets arenot efiicient because it is difficult to direct the jets at angles toclean the bottom of the bore hole and have sufficient upflow velocity tocarry the cuttings therewith. This is particularly true in slim holedrilling because the jets are almost vertical and in opposition to theupward flow. It is obvious that such conditions are not conducive tosatisfactory removal of the cuttings, and the cuttings accumulate in thebottom of the hole, so that the cutters continue to roll upon thecuttings and sludge.

The bit of the above mentioned application overcomes these difficultiesby providing a more eiiicient arrangement of the cutters and a radialjet that discharges through the rotary axis of one of the cutters tosweep the bottom of the hole of cuttings, but the cuttings tend to lagand pile up in the corner of the bore hole, so that the teeth of theoutside cutter must roll over these accumulating cuttings.

Therefore, the principal objects of the present invention are to carrythe cutters on an offset body portion of the bit, as described in saidapplication, and to provide a tangential jet that sweeps into the bottomcorner of the hole in following relation with the radial jet, to assureremoval of the cuttings and a clean bottom hole surface on which theroller cutters will act with greater efiiciency.

It is also an object of the invention to provide the bit with anupwardly directed jet forwardly of the sweep jets to induce upward flowof the cuttings from the sweep jets up the side of the bore hole.

In accomplishing these and other objects of the invention as hereinafterpointed out, I have provided improved structure, the preferred form ofwhich is illustrated in the accompanying drawings, wherein:

FIG. 1 is a vertical section through the bottom end of a bore hole andshowing a drill bit therein which embodies the features of the presentinvention, the section being taken on the line 1-1 of FIG. 2 and lookingin the direction of the arrows.

FIG. 2 is a cross section through the bore hole and showing the drillbit in end view, the section being taken on the line 22 of FIG. 1 andlooking upwardly as indicated by the arrows.

FIG. 3 is a cross section on the line 3-3 of FIG. 1.

FIG. 4 is a vertical section through the bit on the line 44 of FIG. 3and showing the upwardly directed jet.

FIG. 5 is a section of the drill bit on the line 5-5 of FIG. 2, showingthe flow channel supplying the tangential jet.

FIG. 6 is a fragmentary section through the tangential jet taken on theline 6-6 of FIG. 5.

FIG. 7 is a diagrammatic view showing the relative discharge of thejets.

FIG. 8 is a similar elevational view.

Referring more in detail to the drawings:

1 designates a drill bit constructed in accordance with the presentinvention to drill earth formations 2, as in drilling a bore hole 3 fromthe earths surface to substantial depths. The drill bit 1 includes abody member 4, preferably composed of sector shaped sections 5, 6 and 7,suitably connected together, as, for example, by welds 8 (FIG. 3). Thebody 4 of the drill bit includes an externally threaded pin 9 adapted tobe connected to a drilling stem 10. The drilling stem is made up of aplurality of interconnected stands of drill pipe as in usual practice,and is rotated by a rotary mechanism (not shown) at the top of the borehole. The pin 9 is concentric with the rotary axis 11 of the drill stem,but is eccentric with the axis 12 of the body of the bit, that is, theaxis 12 is offset from the axis 11.

The sections 5 and 6 are each provided with a depending arm 13 14 and15, respectively. In the present instance the outer faces of the armsare formed transversely thereof on arcs about the axis 12. The arcuatefaces of the arms merge with the annular face 16 of the body portion ofthe drill bit, so that the body portion of the drill bit below theshoulder 10 is offset from the rotary axis 11 on the axis 12. When thedrill stem 10 is located concentrically with the bore hole 3, thedepending arm 13 is relatively close to the wall of the bore hole and ison the side of the axis 12. The other arms 14 and 15 are spacedcircumferentially from the arm 13 and from each other and the arcuatefaces thereof and the annular face 16 of the body portion 4 are spacedfrom the wall of the bore hole to provide an upflow passageway 18therebetween of generally crescent shaped cross section. The inner orfacing sides 19 of the arms are generally fiat and diverge outwardlyand, downwardly to provide backing for the respective cutters 20, 21 and22. Extending downwardly and inwardly from each of the inner face sides19 of the arms are spindles 23, 24 and 25, respectively. Located on eachof the spindles are antifriction bearings 26 for journaling the cuttersthereon.

The cutters 20, 21 and 22 have generally conical bodies 27, with theperipheries thereof provided with teeth 28 and which are arranged inspaced apart circular series, with the circular series of teeth on eachcutter offset from the circular series of teeth on the other cutters, sothat the teeth of the cutters cooperate to act on the entire area of thebottom of the hole when the bit is rotated by the drilling stem. Theconical body portions and teeth of the cutters may generally correspondwith the body portions and teeth of conventional cutters, but instead ofrolling in circular paths concentric with the rotary axis 11 of thedrill stem, they roll in paths generally concentric with the offset axis12 and therefore gyrate within the bore hole.

The teeth of the cutters produce different patterns of cuts, so that thecuts produced by a tooth of one cutter are out of registry with the cutsproduced by the teeth of the other cutters. The cutter 20 produces thefull diameter of the bore hole 3, while the other cutters 21 and 22cooperate to chip or cut away the bottom of the bore hole over whichthey are caused to revolve. In other words, all of the cutters roll inpaths about the axis 12, but the base teeth 29 of the cutter 20 make awider sweep to produce a hole of larger diameter than the overalldiameter of the bit, and which will be readily noted by comparing theoverall diameter of the bit with the diameter of the bore hole as shownin FIGS. 1 and 2. It is,

therefore, obvious that the bit, being of less overall diameter than thediameter of the bore hole, may be readily raised and lowered through thebore hole, without con- 'tacting the teeth of the cutters with the wallof the bore hole, by shifting the drill stem laterally to bring'the axis12 into registry with the center line, or axis 11. In this way, a freespace is maintained between the path of the cutters at the lower end ofthe upflow passageway 18 that progressively travels around the wall ofthe bore hole. As above stated the bit may be readily removed or loweredthrough a casing or an upper portion of the bore hole that may be ofsmaller diameter than the diameter to be drilled by the bit. Also, thepaths of the cutters are constantly shifting position as the bit isrotated about the axis of the drill stem to enhance the drilling rate atwhich the bit penetrates the formation.

The bodies of the outer cutter 20 and the cutter 22 are generally of amore truncated shape than the cutter '21, which latter cutter is ofgenerally conical shape to assure cutting out of the center of the borehole (see FIGS. 1, 2 and 3). The cutters have concentric recesses 31extending inwardly from the base faces 32 thereof to accommodate thebearings 26. The recesses 31 have a smaller diametered extension tosubstantially conform to the diameter of the spindles at the endsthereof. The smaller ends of the cutters 20 and 22 have inwardlyextending annular flanges 32' which close over the inner ends of thespindles 23 and 25 and provide axial openings 33 registering with axialbores 34 of the spindles 23 and 25 that extend through the dependingarms.

Extending through the opening 33 of the cutter 22 and entirely throughthe registering bore 34 of the spindle is a solid shank 35 having a head36- thereon of larger diameter than the opening 33 to engage the cutterfor holding the cutter on the spindle, as shown in FIG. 4. The shank 35is fixed in the bore by welding the outer end thereof to the arm 15, asindicated at 37 (FIG. 4).

The opening 33 of the cutter 20 and the bore 34 of the spindle 23 are oflarger diameter to accommodate a tubular shank 38 of larger diameterthan the shank 35 and which has an inner diameter of suflicient size toprovide a flow passageway 39 for the discharge of a jet of drillingfluid across the bore hole in sweeping contact with the bottom thereofand into the open space at the bottom of the upflow passageway 18 asindicated in FIGS. 1, 2, 7 and 8. The tubular shank also has a head 40lapping the end of the cutter 20, and the end of the shank 38 is weldedto the arm, as indicated at 41, FIG. 1, for retaining the cutter on itsspindle.

The flow passage 39 terminates short of the welded end of the tubularshank and has a port 42 in communication with a channel or passage 43that connects with an axial bore or recess 44 in the pin 9. The axialbore or recess 44 is in turn connected with the downflow passageway 45of the drill stem.

The cutter 21, that is of more conical shape, is mounted 4 on thespindle 24 by roller bearings 26 similarly to the other cutters,however, the spindle 24 is a solid spindle, as shown in FIG. 5, and thecutter is retained thereon by a split ring 46, as indicated.

The base faces of all of the cutters and the corresponding inner facesof the arms may be provided with wear resistant material, or rings 47and 48, as illustrated in FIG. 5, to take the end thrust of the cutters.The under side of the heads and the registering annular portions of theends of the cutters also have wear resistant material inserts 49 and 50.The inner ends of the cutters may also have small ports 51 that aredrilled therein, as shown in FIG. 4.

The body section 6 has a passageway 52 leading from the recess 44 anddischarging through a port 53 located in the lower edge of the arm 14 onthe advance side thereof at an angle of 35 to 45 to discharge agenerally downwardly and tangentially directed jet for sweeping thebottom corner of the bore hole, as later described.

It is thus obvious that the recess 44 provides passageway means to whichthe passageways 43, 52 and 54 are all connected.

The body section 7 has a passageway 54 leading from the recess 44 anddischarging through an upwardly directed port 55 on the side of the bodymember that carries the arms 14 and 15, as shown in FIGS. 3 and 4.

In assembling the bit at the factory, the roller bearings 26 with thecutters are placed on the spindles of the respective segmental sections5, 6 and 7. The cutter 21 is secured to its spindle by the split ring46. The cutters 20 and 22 are secured to their spindles by inserting theshanks 38 and 35 through the opening 33 of the cutters and into thebores 34 of the spindles 23 and 25 until the heads 40 and 36 thereofmake contact with the flanges 32 of the cutters. The outer ends of theshanks are then welded to the arms 13 and 15, respectively. Aftermounting the cutters, the sections 5, 6 and 7 are brought together andwelded, as indicated by the numeral 8.

In using the drill bit constructed and assembled as described, it isattached to the drill stem and the drill stem is lowered into the borehole, in accordance with the usual practice of running in the drillingstring. Since the overall diameter of the bit is less than the diameterof the hole, it may be passed through a cased upper portion of the borehole without damage to the teeth of the bit. The bit may be used fordeepening a hole to a larger diameter and successfully lowered todrilling position as long as the hole is no smaller than the overalldiameter of the bit.

With the bit in drilling position on the bottom of the hole, a drillingfluid is circulated under pressure downwardly through the passageway 45of the drill stem 10 for return flow exteriorly of the drill pipe to thetop of the bore hole. Upon starting rotation of the drilling stern inthe direction of the arrow, FIGS. 2, 3, 7 and 8, the cutters 20, 21 and22 will revolve on their spindles 23, 24 and 25 and gyrate in eccentriccircular paths over the bottom of the hole, with the teeth of thecutters bearing into and chipping away the formationbeing drilled. Thecutter 20 moves circularly as it is gyrated about the axis of the drillstem, to maintain the gauge of the bore hole. The teeth of the othercutters cooperate with the teeth of the cutter 20 to cover the entirebottom of the hole.

Simultaneously with rotation of the drill stem, a portion of thedrilling fluid being circulated passes from the axial bore or recess 44through the passageway 43, port 42, and flow passageway 39 of thetubular shank 38, to emit a high pressure jet 56 that is directeddownwardly and radially incidental to the position of the passageway 39to impinge against the bottom of the bore hole and sweep between thecutters 21 and 22 into the open space at the bottom of the passageway 18to the wall of the bore hole, as shown in FIGS. 1, 2, 7 and 8, whichdiverts the fluid of the jet upwardly to sweep away the cuttings fromthe bottom of the hole and carry the cuttings upwardly through theupflow passageway 18 at the side of the bit. During rotation of the bit,the jet 56 maintains its substantially radial discharge and is gyratedabout the rotary axis 11 to present the force of the jet in progressivesweeping contact into the bottom space during each revolution of thedrill stem. The cuttings made by the teeth of the bit are positivelyswept from the bottom of the bore hole and most of them are divertedupwardly, however, some of the cuttings tend to lodge in the corner 57of the bore hole. But with the bit of the present invention, drillingfluid from the recess 44 flows through the passageway 52 and isdischarged as a high pressure jet 58 generally downwardly andtangentially into the corner 57 of the open space in the bottom of thepassageway 13 in following relation with the jet 56. The jet 58 thussweeps about the corner of the bore hole in following relation with thejet, to sweep out any of the cuttings or sludge that might tend toaccumulate therein. Simultaneously, a jet 59 is emitted through theupwardly directed port 55 to maintain the upward flow at high velocityto assure elevation of the cuttings to the top of the bore hole. Thusthe teeth of the cutters rotate upon a clean bottom and effect a morerapid and eflicient chipping away of the formation.

From the foregoing, it is obvious that the features of offsetting theaxis of the bit, the discharge of the drilling fluid through the axis ofthe outermost cutter, and tangential discharge through the arm 14,together with the relation of the cutters, all cooperae to promotegreater cutting efliciency of the bit and removal of the cuttings. WhatI claim and desire to secure by Letters Patent is: 1. A rotary drill bitfor drilling bore holes into earth formations and the like, including abody member having a drill stem connection by which the drill bit isrotated and having a passage- Way means within said body member anddrill stem connection through which a drilling fluid is supplied whenthe drill bit is in use, arms depending from the body member one ofwhich is on the side of an offset axis from the rotational axis of thedrill stem connection and the other of said arms being circumferentiallyspaced from said one arm and from each other, spindles carried by saidarms and extending downwardly and inwardly toward said offset axis, and

conical cutters on said spindles to roll in circular paths about theoffset axis and in gyratory motion about the axis of the drill stemconnection to maintain an open space between said cutters and the wallof the bore hole that is opposite the conical cutter carried by said onearm and which travels progressively around the wall of the bore holewith the gyratory movement of the cutters to maintain an unobstructedupflow passageway from the bottom of the bore hole upwardly at the sideof the drill bit,

said one arm and spindle carried thereby having a flow passagewayconnected with said passageway means for discharging a jet of drillingfluid through said spindle to wash cuttings substantially radiallyacross the bottom of the bore hole and into said open space and one ofthe other of said arms having a flow passageway also connected with saidpassageway means for discharging a jet of drilling fluid from the lowerend of said arm tangentially into said open space to sweep away thecuttings washed into said space by the radial jet of drilling fluid toclear the bottom of said space of cuttings whereby the cutters roll upona bottom hole substantially free of cuttings as they are gyrated aboutthe rotary axis.

2. A rotary drill bit for drilling bore holes into earth formations andthe like, including a body member having a drill stem connection bywhich the drill bit is rotated and having a passageway means within saidbody and drill stem connection through which a drilling fluid issupplied when the drill bit is in use,

arms depending from the body member one of which is on the side of anoffset axis from the rotational axis of the drill stem connection andthe other of said arms being circumferentially spaced from said one armand from each other,

spindles carried by said arms and extending downwardly and inwardlytoward said oifset axis, and

conical cutters on said spindles to roll in circular paths about theoffset axis and in gyratory motion about the axis of the drill stemconnection to maintain an open space between said cutters and the wallof the bore hole that is opposite the conical cutter carried by said onearm and which travels progressively around the wall of the bore holewith the gyratory movement of the cutters to maintain an unobstructedupflow passageway from the bottom of the bore hole upwardly at the sideof the drill bit,

said one arm and spindle carried thereby having a flow passagewayconnected with said passageway means for discharging a jet of drillingfluid through said spindle to wash cuttings substantially radiallyacross the bottom of the bore hole and into said open space and thetrailing one of the said other arms relatively to the direction ofrotation having a flow passageway also connected with said passagewaymeans and discharging a jet of drilling fluid from the lower end of thesaid other arm tangentially into said open space in the direction ofrotation to sweep away the cuttings washed into said space by the radialjet of drilling fluid to clear the bottom of said space of cuttingswhereby the cutters roll upon a. bottom hole substantially free ofcuttings as they are gyrated about the rotary axis,

said body member having a flow passageway also connected with saidpassageway means and discharging upwardly on the side of the body memberthat carries the said other arms for emitting a jet of drilling fluidinto said open space to induce upward flow of cuttings dislodged by saidfirst named jets.

3. A rotary drill bit for drilling bore holes into earth formations andthe like, including a body member having a drill stem connection bywhich the drill bit is rotated and having a passageway means within saidbody member and drill stem connection through which a drilling fluid issupplied when the drill bit is in use,

arms depending from the body member one of which is on the side of anoffset axis from the rotational axis of the drill stem connection andthe other of said arms being circumferentially spaced from said one armand from each other,

spindles carried by said arms and extending downwardly and inwardlytoward said olfset axis, and

conical cutters on said spindles to roll in circular paths about theoffset axis and in gyratory motion about the axis of the drill stemconnection to maintain an open space between said cutters and the wallof the bore hole that is opposite the conical cutter carried by said onearm and which travels progressively around the wall of the bore holewith the gyratory movement of the cutters to maintain an unobstructedupflow passageway from the bottom of the bore hole upwardly at the sideof the drill bit,

said one arm and spindle carried thereby having a flow passagewayconnected with said passageway means for discharging a jet of drillingfluid through said spindle to wash cuttings substantially radiallyacross the bottom of the bore hole and into said open space and theother of said arms which is trailing said open space having a flowpassageway also connected with said passageway means and opening fromthe lower end of the said other arm for discharging a jet of drillingfluid tangentially into said open space in the direction of rotation tosweep away the cuttings washed into said space by the radial jet ofdrilling fluid to clear the bottom of said space of cuttings whereby thecutters roll upon a bottom hole substantially free of cuttings as theyare gyrated about the rotary axis,

said body member having a flow passageway also connected with saidpassageway means and discharging upwardly on the side of the body memberwhich carries the said other arms to induce upward flow of cuttingsdislodged by said first named jets.

References Cited in the file of this patent UNITED STATES PATENTS 82,614,810 Goolsbee Oct. 21, 1952 2,634,101 Sloan Apr. 7, 1953 2,746,721Moore May 22, 1956 2,776,115 Williams Jan. 1, 1957 2,805,045 GoodwinSept. 3, 1957 3,014,544 Steen Dec. 26, 1961 3,081,829 Williams Mar. 19,1963 3,099,324 Kucera et a1. July 30, 1963 3,111,179 Albers et a1 Nov.19, 1963 OTHER REFERENCES Kucera, C. M., and Boice, E. G.: New Jet BitsVent Ports Pass Lab and Field Tests, in Drilling, January 1959, p. 101.

1. A ROTARY DRILL BIT FOR DRILLING BORE HOLES INTO EARTH FORMATIONS ANDTHE LIKE, INCLUDING A BODY MEMBER HAVING A DRILL STEM CONNECTION BYWHICH THE DRILL BIT IS ROTATED AND HAVING A PASSAGEWAY MEANS WITHIN SAIDBODY MEMBER AND DRILL STEM CONNECTION THROUGH WHICH A DRILLING FLUID ISSUPPLIED WHEN THE DRILL BIT IS IN USE, ARMS DEPENDING FROM THE BODYMEMBER ONE OF WHICH IS ON THE SIDE OF AN OFFSET AXIS FROM THE ROTATIONALAXIS OF THE DRILL STEM CONNECTION AND THE OTHER OF SAID ARMS BEINGCIRCUMFERENTIALLY SPACED FROM SAID ONE ARM AND FROM EACH OTHER, SPINDLESCARRIED BY SAID ARMS AND EXTENDING DOWNWARDLY AND INWARDLY TOWARD SAIDOFFSET AXIS, AND CONICAL CUTTERS ON SAID SPINDLES TO ROLL IN CIRCULARPATHS ABOUT THE OFFSET AXIS AND IN GYRATORY MOTION ABOUT THE AXIS OF THEDRILL STEM CONNECTION TO MAINTAIN AN OPEN SPACE BETWEEN SAID CUTTERS ANDTHE WALL OF THE BORE HOLE THAT IS OPPOSITE THE CONICAL CUTTER CARRIED BYSAID ONE ARM AND WHICH TRAVELS PROGRESSIVELY AROUND THE WALL OF THE BOREHOLE WITH THE GYRATORY MOVEMENT OF THE CUTTERS TO MAINTAIN ANUNOBSTRUCTED UPFLOW PASSAGEWAY FROM THE BOTTOM OF THE BORE HOLE UPWARDLYAT THE SIDE OF THE DRILL BIT, SAID ONE ARM AND SPINDLE CARRIED THEREBYHAVING A FLOW PASSAGEWAY CONNECTED WITH SAID PASSAGEWAY MEANS